Method for producing a helix and permanent mold for casting a helix

Patent metadata

Field	Value
Publication number	US-12296375-B2
Application number	US-201917250866-A
Country	US
Kind code	B2
Filing date	Sep 19, 2019
Priority date	Sep 19, 2018
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

A permanent mold can include mold halves which can be joined together on a mold separation plane. The mold halves of the permanent mold are joined together such that the permanent mold has a cavity, which defines the shape of the helix or the shape of a bent-up helix, when the permanent mold is joined together. The specified helix or the bent-up helix has a flattened profiled winding cross-section which has two opposite flat faces, an outer face and an inner face opposite the outer face. The mold separation plane runs at least partly along the flat faces from the inner face to the outer face, wherein the permanent mold has a bulge which extends along the mold separation plane and protrudes into the cavity at least in a region in which the mold separation plane runs along one of the flat faces such that the cast body is provided with recesses on the flat faces.

First claim

The invention claimed is:

1. A method for producing a helix, the method comprising:
providing a permanent mold including a first mold half and a second mold half configured to be joined together in a mold parting plane;
joining together the first mold half and the second mold half of the permanent mold in the mold parting plane so that the permanent mold, when joined, has a cavity that defines a form of the helix or a form of a bent-up helix, wherein the defined helix or bent-up helix has a flattened winding cross-section profile including:
a first flat side;
a second flat side located opposite to the first flat side;
an outer side; and
an inner side opposite the outer side;

introducing a casting material into the cavity to produce a casting having the form of the helix defined by the cavity or the form of the bent-up helix;
opening the permanent mold; and
removing the casting, wherein the first flat side and the second flat side of the casting face each other when the casting is in the form of the helix or is brought into the form of the helix, wherein a mold parting line sectionally runs along the first flat side and the second flat side from the inner side to the outer side, and wherein the permanent mold, at least in a portion where the mold parting line runs along at least one of the first flat side or the second flat side, includes a protrusion extending along the mold parting line that projects into the cavity so that the casting contains a first indentation on the first flat side and a corresponding second indentation on the second flat side.

2. The method according to claim 1 , wherein the permanent mold, in each portion where the mold parting line runs along the first of the flat side, includes a first set of multiple protrusions extending along the mold parting line protruding into the cavity, such that the casting includes, on the first flat side, with a corresponding first set of indentations running in the mold parting line.

3. The method according to claim 2 , wherein the permanent mold, in each portion where the mold parting line runs along the second flat side, includes at least one of: a second set of multiple protrusions extending along the mold parting line, such that the casting includes a second set of indentations running in the mold parting line, or includes multiple recesses extending along the mold parting line, such that the casting includes on the first flat side in the mold parting line with the first set of indentations, and on the second flat side in the mold parting line with protrusions, wherein the protrusions lie within the first set of indentations when the casting is in the form of the helix.

4. The method according to claim 1 , wherein the casting is bent into the form of the helix after removal.

5. The method according to claim 1 , wherein the casting material comprises at least one of: aluminum or copper.

6. The method according to claim 1 , wherein the casting is performed at a temperature above 1100° C.

7. The method according to claim 1 , wherein introducing the casting material into the cavity includes using a die casting method, a permanent mold casting method, or a low-pressure die casting method.

8. The method according to claim 1 , wherein the mold parting line runs at least in sections along at least one of: the outer side, the inner side, or from edges of a winding cross-section profile, and burrs extending on at least one of: the outer side, the inner side or the edges of the casting in the mold parting line are removed after the casting has been removed.

9. The method according to claim 8 , wherein the cavity, in at least one portion where the mold parting line runs along at least one of: the outer side, the inner side or the edges of the winding cross-section profile, include multiple additional indentations to produce multiple sacrificial structures which extend along at least one of: the outer side, the inner side, or the edges of the casting in the mold parting line, wherein the multiple sacrificial structures are removed in a reworking step after the casting has been removed, together with the burrs that run along them.

10. The method according to claim 8 , wherein a mandrel is inserted into the bent-up helix in order to at least one of: remove the burrs on the inner side or to bend together the bent-up helix to form the helix.

11. The method according to claim 8 , wherein the mold parting line, in sections in which the mold part line runs along at least one of the outer side, the inner side, or one or more the edges of the winding cross-section profile, encloses an angle (α) of more than 0° and less than 180° with at least one of the outer side or the inner side.

12. A permanent mold for casting a helix, comprising:
a first mold half; and
a second mold half;
wherein, the first mold half and the second mold half are configured to be joined together in a mold parting plane, the mold parting plane forming a mold parting line, wherein the first mold half and the second mold half, when joined, have a cavity that defines, for the casting, a form of at least one of the helix or a bent-up helix with a flattened winding cross-section profile, wherein a casting material is introduced into the cavity to produce the casting, wherein the winding cross-section profile has a first flat side and a second flat side located opposite the first flat side, an outer side, and an inner side located opposite the outer side, wherein the first flat side and the second flat side face one another when the casting is in the form of the helix or is brought into the form of the helix, wherein the mold parting line, within each winding of the helix or bent-up helix defined by the cavity, runs along the first flat side and the second flat side from the inner side to the outer side, and wherein the cavity, at least in one portion where the mold parting line runs along the first flat side and the second flat side, has a protrusion extending along the mold parting line.

13. The permanent mold of claim 12 , wherein the mold parting line runs at least in sections along at least one of: the outer side, the inner side, or from a first edge or a second edge of a winding cross-section profile.

14. The permanent mold of claim 12 , wherein the mold parting line includes a set of multiple protrusions extending along the mold parting line protruding into the cavity, such that the casting includes, on the first flat side, with a corresponding set of indentations running in the mold parting line.

15. The permanent mold of claim 14 , wherein in each portion where the mold parting line runs along the second flat side, the mold includes:
a second set of multiple protrusions extending along the mold parting line such that the casting includes a second set of indentations running in the mold parting line.

16. The permanent mold of claim 14 , wherein in each portion where the mold parting line runs along the second flat side, the mold includes:
multiple recesses extending along the mold parting line such that the casting includes, on the first flat side in the mold parting line with the first set of indentations, and on the second flat side of the mold parting line with protrusions located to lie within the first set of indentations when the casting is in the form of the helix.

17. The permanent mold of claim 12 , wherein the casting material comprises at least one of aluminum or copper.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Wöstmann Franz-Josef
• Heuser Michael
• Busse Matthias

Classifications

• H01F41/04

  for manufacturing coils {(coils for transformer or inductances H01F27/28)} · CPC title

• H01F5/00

  Coils (superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00) · CPC title

• B22D31/002

  Cleaning, working on castings · CPC title

• B22D25/02

  by its peculiarity of shape; of works of art {(cylinders, pistons B22D15/02)} · CPC title

• B22D17/22

  Dies (manufacture, see the appropriate class, e.g. B23P15/24); Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies · CPC title